Improved asphalt material

ABSTRACT

Asphalt product made from or containingZ1) from 90 wt % to 98 wt % of mineral aggregate; andZ2) from 2 wt % to 10 wt % of a bitumen composition made from or containingT1) from 99 wt % to 75 wt % of bitumen, andT2) from 1 wt % to 25 wt % of a polymer composition made from or containingA) 5-35% by weight of a propylene ethylene copolymer;B) 20-50% by weight of an ethylene homopolymer; andC) 30-60% by weight of a terpolymer of ethylene, propylene and 1-butene derived units.

FIELD OF THE INVENTION

In general, the present disclosure relates to the field of chemistry.More specifically, the present disclosure relates to polymer chemistry.In particular, the present disclosure relates to an asphalt compositionmade from or containing mineral aggregate and a mixture made from orcontaining bitumen and polymer compositions.

BACKGROUND OF THE INVENTION

Asphalt is a mixture of bitumen with mineral aggregate and optionallyvarious additives.

In some instances, polymer compositions modify bitumen.

In some instances, the modified-bitumen mixtures are used in roofingapplications.

SUMMARY OF THE INVENTION

In a general embodiment, the present disclosure provides an asphaltproduct made from or containing:

Z1) from 90 wt % to 98 wt % of mineral aggregate; and

Z2) from 2 wt % to 10 wt % of a bitumen composition made from orcontaining

T1) from 99 wt % to 75 wt % of bitumen, and

T2) from 1 wt % to 25 wt % of a polymer composition made from orcontaining

A) 5-35% by weight of a propylene ethylene copolymer containing 15% byweight or less of a fraction soluble in xylene at 25° C. (XS_(A)), theamount of the fraction XS_(A) being referred to the weight of A); andfrom 0.5 wt % to 7.0 wt % of ethylene derived units;

B) 20-50% by weight of an ethylene homopolymer having 5% by weight orless of a fraction soluble in xylene at 25° C. (XS_(B)) referred to theweight of (B); and

C) 30-60% by weight of a terpolymer, wherein the terpolymer containsethylene, propylene and 1-butene derived units and containing from 45%to 65% by weight of ethylene units; and from 15% to 38% by weight of1-butene units; and containing from 30% to 85% by weight of a fractionsoluble in xylene at 25° C. (XS_(C)), the amount of ethylene units,1-butene units, and the fraction XS_(C) being referred to the weight of(C);

the amounts of (A), (B) and (C) being referred to the total weight of(A)+(B)+(C), the sum of the amount of (A)+(B)+(C) being 100 wt %;

the amounts, wt %, of T130 T2 being 100 wt %.

DETAILED DESCRIPTION OF THE INVENTION

In some embodiments, the present disclosure provides an asphalt productmade from or containing:

Z1) from 90 wt % to 98 wt %; alternatively from 93 wt % to 97 wt %;alternatively from 96 wt % to 94 wt %; of mineral aggregate; and

Z2) from 2 wt % to 10 wt %; alternatively from 3 wt % to 7 wt %;alternatively from 4 wt % to 6 wt %; of a bitumen composition made fromor containing

T1) from 99 wt % to 75 wt %; alternatively from 98 wt % to 80 wt %;alternatively from 97 wt % to 90 wt %; alternatively from 97 wt % to 92wt %; of bitumen; and

T2) from 1 wt % to 25 wt %; alternatively from 2 wt % to 20 wt %;alternatively from 3 wt % to 10 wt %; alternatively from 3 wt % to 8 wt%; of a polymer composition made from or containing

A) 5-35% by weight; alternatively 10-30% by weight; alternatively 15-23%by weight; of a propylene ethylene copolymer containing 15% by weight orless; alternatively 13 wt % or less; alternatively 10 wt % or less; of afraction soluble in xylene at 25° C. (XS_(A)), the amount of thefraction XS_(A) being referred to the weight of A); and from 0.5 wt % to7.0 wt %; alternatively from 1.0 wt % to 6.0 wt %; alternatively from1.5 wt % to 4.5 wt %; of ethylene derived units;

B) 20-50% by weight; alternatively 25-45% by weight; alternatively30-40% by weight; of an ethylene homopolymer having 5% by weight orless; alternatively 4 wt % or less; alternatively 3 wt % or less; of afraction soluble in xylene at 25° C. (XS_(B)), the amount of thefraction XS_(B) being referred to the weight of (B); and

C) 30-60% by weight; alternatively 35-55% by weight; alternatively40-50% by weight; of a terpolymer of ethylene, propylene and 1-buteneand containing from 45% to 65% by weight; alternatively from 48% to 62%by weight; alternatively from 50% to 60% by weight; of ethylene units;and from 15% to 38% by weight; alternatively from 18% to 33% by weight,alternatively from 20% to 30% by weight; of 1-butene units; andcontaining from 30% to 85% by weight; alternatively from 35% to 50% byweight; of a fraction soluble in xylene at 25° C. (XS_(C)), the amountof ethylene units, 1-butene units, and the fraction XS_(C) beingreferred to the weight of (C);

the amounts of (A), (B) and (C) being referred to the total weight of(A)+(B)+(C), the sum of the amount of (A)+(B)+(C) being 100 wt %; theamounts, wt %, of T1+T2 being 100 wt %.

In some embodiments, mineral aggregate component Z1) is selected fromthe group consisting of sand, gravel, limestone, crushed stone, slag,and mixtures thereof. In some embodiments, the mineral aggregateparticles include calcium-based aggregates, siliceous based aggregates,and mixtures thereof. In some embodiments, the calcium-based aggregatesare limestone. In some embodiments, aggregates are selected for asphaltpaving applications based on several criteria, including physicalproperties, compatibility with the bitumen to be used in theconstruction process, availability, and ability to provide a finishedpavement that meets the performance specifications of the pavement layerfor the traffic projected over the design life of the project.

Component Z2) is made from or containing bitumen T1) and a polymercomposition T2).

In some embodiments, bitumen (T1) includes solid, semi-solid or viscousdistillation residues of the petroleum refinery process, consistingpredominantly of high molecular weight hydrocarbons. In someembodiments, the structure is partially altered. In some embodiments,the structure is altered by oxidation.

Polymer composition T2) is made from or containing components A), B) andC).

In some embodiments, (A) has a melt flow rate (230° C./2.16 kg) between50 and 200 g/10 min; alternatively between 80 and 170 g/10 min.

In some embodiments, the ethylene homopolymer (B) contains up to 5% byweight; alternatively up to 3% by weight; of comonomer units. In someembodiments, the comonomer units derive from one or more comonomersselected from C₃ to C₈ alpha-olefins. In some embodiments, thealpha-olefin comonomers are selected from the group consisting ofpropylene, butene-1, pentene-1, 4-methylpentene-1, hexene-1, andoctene-1. In some embodiments, the alpha-olefin comonomers are selectedfrom the group consisting of propylene and 1-butene. In someembodiments, the ethylene homopolymer (B) does not contain additionalcomonomer units.

In some embodiments, the ethylene homopolymer (B) has a melt flow rate(230° C./2.16 kg) between 0.1 and 50 g/10 min.; alternatively between0.1 and 30 g/10 min; alternatively between 0.1 and 10 g/10 min.

In some embodiments, the ethylene homopolymer (B) has a density(determined according to ISO 1183 at 23° C.) of from 0.940 to 0.965g/cm³.

In some embodiments, components (A)+(B) blended together have a meltflow rate (230° C./2.16 kg) between 0.1 and 70 g/10 min.; alternativelybetween 1 and 50 g/10 min; alternatively between 8 and 40 g/10 min.

In some embodiments, the polyolefin composition (A)+(B)+(C) has a meltflow rate (230° C./2.16 kg) between 0.5 to 25 g/10 min; alternativelyfrom 0.8 to 20.0 g/10 min; alternatively from 1.0 to 18.0 g/10 min.

In some embodiments, the xylene soluble fraction at 25° C. of thepolyolefin composition (A+B+C) has an intrinsic viscosity [η] (measuredin tetrahydronaphthalene at 135° C.) between 2.4 and 3.5 dl/g,alternatively between 2.5 and 3.3 dl/g.

As used herein, the term “copolymer” refers to a polymer containing twokinds of comonomers, such as propylene and ethylene or ethylene and1-butene. As used herein, the term “terpolymer” refers to a polymercontaining three kinds of comonomers, such as propylene, ethylene and1-butene.

In some embodiments, the polyolefin composition is prepared by asequential polymerization, including at least three sequential steps,wherein components (A), (B) and (C) are prepared in separate subsequentsteps, operating in each step, except the first step, in the presence ofthe polymer formed and the catalyst used in the preceding step. In someembodiments, the catalyst is added in the first step and not insubsequent steps. In some embodiments, the catalyst remains active forthe subsequent steps.

In some embodiments, the polymerization is a continuous process. In someembodiments, the polymerization is a batch process. In some embodiments,the polymerization is carried out in liquid phase, in the presence ornot of inert diluent, or in gas phase, or by mixed liquid-gastechniques. In some embodiments, the polymerization is carried out ingas phase.

In some embodiments, the temperature for the polymerization steps isfrom 50 to 100° C. In some embodiments, the pressure for thepolymerization steps is atmospheric or higher.

In some embodiments, the molecular weight is regulated. In someembodiments, the molecular weight regulator is hydrogen.

In some embodiments, the polymerizations are carried out in the presenceof a Ziegler-Natta catalyst. In some embodiments, a Ziegler-Nattacatalyst is made from or containing the product of the reaction of anorganometallic compound of group 1, 2 or 13 of the Periodic Table ofelements with a transition metal compound of groups 4 to 10 of thePeriodic Table of Elements (new notation). In some embodiments, thetransition metal compound is selected from the group consisting ofcompounds of Ti, V, Zr, Cr and Hf. In some embodiments, the transitionmetal compound is supported on MgCl₂.

In some embodiments, the catalysts are made from or containing theproduct of the reaction of the organometallic compound of group 1, 2 or13 of the Periodic Table of elements, with a solid catalyst componentmade from or containing a Ti compound and an electron donor compoundsupported on MgCl₂.

In some embodiments, the organometallic compounds are aluminum alkylcompounds.

In some embodiments, the polymer composition is obtained by using aZiegler-Natta polymerization catalyst, alternatively a Ziegler-Nattacatalyst supported on MgCl₂, alternatively a Ziegler-Natta catalyst madefrom or containing the product of reaction of:

1) a solid catalyst component made from or containing a Ti compound andan electron donor (internal electron-donor) supported on MgCl₂;

2) an aluminum alkyl compound (cocatalyst); and, optionally,

3) an electron-donor compound (external electron-donor).

In some embodiments, the solid catalyst component (1) contains, aselectron-donor, a compound selected from the group consisting of ethers,ketones, lactones, compounds containing N, P and/or S atoms, and mono-and dicarboxylic acid esters.

In some embodiments, the catalysts are as described in U.S. Pat. No.4,399,054 and European Patent No. 45977.

In some embodiments, the electron-donor compounds are selected from thegroup consisting of phthalic acid esters and succinic acid esters. Insome embodiments, the phthalic acid ester is diisobutyl phthalate.

In some embodiments, the succinic acid esters are represented by theformula (I):

wherein the radicals R₁ and R₂, equal to or different from each other,are a C₁-C₂₀ linear or branched alkyl, alkenyl, cycloalkyl, aryl,arylalkyl or alkylaryl group, optionally containing heteroatoms; theradicals R₃ to R₆ equal to or different from each other, are hydrogen ora C₁-C₂₀ linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkylor alkylaryl group, optionally containing heteroatoms. In someembodiments, the radicals R₃ to R₆ are joined to the same carbon atomand linked together to form a cycle.

In some embodiments, R₁ and R₂ are selected from the group consisting ofC₁-C₈ alkyl, cycloalkyl, aryl, arylalkyl and alkylaryl groups. In someembodiments, R₁ and R₂ are selected from primary alkyls; alternativelybranched primary alkyls. In some embodiments, R₁ and R₂ groups areselected from the group consisting of methyl, ethyl, n-propyl, n-butyl,isobutyl, neopentyl, and 2-ethylhexyl. In some embodiments, R₁ and R₂groups are selected from the group consisting of ethyl, isobutyl, andneopentyl.

In some embodiments, R₃ to R₅ are hydrogen and R₆ is a branched alkyl,cycloalkyl, aryl, arylalkyl and alkylaryl radical having from 3 to 10carbon atoms. In some embodiments, at least two radicals from R₃ to R₆are different from hydrogen and selected from C₁-C₂₀ linear or branchedalkyl, alkenyl, cycloalkyl, aryl, arylalkyl or alkylaryl group,optionally containing heteroatoms. In some embodiments, the two radicalsdifferent from hydrogen are linked to the same carbon atom. In someembodiments, R₃ and R₅ are different from hydrogen and linked todifferent carbon atoms. In some embodiments, R₄ and R₆ are differentfrom hydrogen and linked to different carbon atoms.

In some embodiments, the electron-donors are the 1,3-diethersdescribedin European Patent Application Nos. EP-A-361 493 and 728769.

In some embodiments, cocatalysts (2) are trialkyl aluminum compounds. Insome embodiments, the trialkyl aluminum compounds are selected from thegroup consisting of Al-triethyl, Al-triisobutyl, and Al-tri-n-butyl.

In some embodiments, the electron-donor compounds (3) used as externalelectron-donors (added to the Al-alkyl compound) are selected from thegroup consisting of aromatic acid esters, heterocyclic compounds, andsilicon compounds containing at least one Si—OR bond (where R is ahydrocarbon radical). In some embodiments, the aromatic acid esters arealkylic benzoates. In some embodiments, the heterocyclic compounds areselected from the group consisting of 2,2,6,6-tetramethylpiperidine and2,6-diisopropylpiperidine.

In some embodiments, the silicon compounds have the formula R¹ _(a)R²_(b)Si(OR³)_(c), where a and b are integer numbers from 0 to 2, c is aninteger from 1 to 3 and the sum (a+b+c) is 4; R¹, R² and R³ are alkyl,cycloalkyl or aryl radicals with 1-18 carbon atoms optionally containingheteroatoms.

In some embodiments, the silicon compounds are selected from the groupconsisting of (tert-butyl)₂Si(OCH₃)₂, (cyclohexyl)(methyl)Si (OCH₃)₂,(phenyl)₂Si(OCH₃)₂ and (cyclopentyl)₂Si(OCH₃)₂.

In some embodiments, the 1,3-diethers are used as external donors. Insome embodiments, the internal donor is a 1,3-diethers and the externaldonor is omitted.

In some embodiments, the catalysts are precontacted with smallquantities of olefin (prepolymerization), maintaining the catalyst insuspension in a hydrocarbon solvent, and polymerizing at temperaturesfrom room to 60° C., thereby producing a quantity of polymer from 0.5 to3 times the weight of the catalyst.

In some embodiments, the operation takes place in liquid monomer,producing a quantity of polymer up to 1000 times the weight of thecatalyst.

In some embodiments, component Z2) contains at least one other type ofpolymer, hereinafter identified as component (T3), in addition to thepolymer composition (T2).

In some embodiments, T2 is made from or containing, as component (T3),one or more olefinic or nonolefinic polymers. In some embodiments,polymers (T3) are selected from the group consisting of amorphous oratactic polymers, styrene-butadiene-styrene (SBS) copolymers, ethylenepolyvinyl acetate, low density polyethylene, high density polyethylene,and other polyolefins. In some embodiments, the amorphous polymer is anamorphous polyolefin. In some embodiments, the amorphous polyolefin isamorphous polypropylene. In some embodiments, polymers (T3) are selectedfrom the group consisting of isotactic polypropylene andethylene-propylene random copolymers.

In some embodiments, the additional polymers (T3) are added inquantities greater than or equal to 0.5%, alternatively from 0.5 to 30%,alternatively from 0.5 to 23%, by weight with respect to the weight ofT2. In some embodiments, the total quantity of component T2 and T3 (thatis, the amount of T2+T3) in the bituminous mixture is less than or equalto 40%, alternatively less than or equal to 25%, by weight with respectto the total weight of the mixture.

In some embodiments and for incorporating the polymer composition (T2)and the other components into the bitumen (T1), the mixing process iscarried out at a temperature from 120 to 250° C.; alternatively from130° C. to 180° C.

The following examples are given to illustrate, but not limit thepresent disclosure.

EXAMPLES Characterizations

Xylene-Soluble (XS) Fraction at 25° C.

Solubility in xylene: Determined as follows:

2.5 g of polymer and 250 ml of xylene were introduced into a glass flaskequipped with a refrigerator and a magnetic stirrer. The temperature wasraised in 30 minutes up to the boiling point of the solvent. Theresulting clear solution was then kept under reflux and stirred for 30minutes. The closed flask was then kept for 30 minutes in a bath of iceand water, then in a thermostatic water bath at 25° C. for 30 minutes.The resulting solid was filtered on quick filtering paper. 100 ml of thefiltered liquid was poured into a pre-weighed aluminum container, whichwas heated on a heating plate under nitrogen flow, thereby removing thesolvent by evaporation. The container was then kept in an oven at 80° C.under vacuum until a constant weight was obtained. The weight percentageof polymer soluble in xylene at room temperature was then calculated.

The content of the xylene-soluble fraction is expressed as a percentageof the original 2.5 grams and then, by the difference (complementary to100%), the xylene insoluble percentage (%);

XS of components B) and C) were calculated by using the formula:

XS _(tot) =WaXS _(A) +WbXS _(B)+WcXS_(C)

wherein Wa, Wb and We were the relative amount of components A, B and C,respectively, and (A+B+C=1).

Melt Flow Rate (MFR)

Measured according to ISO 1133 at 230° C. with a load of 2.16 kg, unlessotherwise specified.

Intrinsic Viscosity (IV)

The sample was dissolved in tetrahydronaphthalene at 135° C. and thenpoured into a capillary viscometer. The viscometer tube (Ubbelohde type)was surrounded by a cylindrical glass jacket; this setup allowed fortemperature control with a circulating thermostatic liquid. The downwardpassage of the meniscus was timed by a photoelectric device.

The passage of the meniscus in front of the upper lamp started thecounter which had a quartz crystal oscillator. The counter stopped asthe meniscus passed the lower lamp. The efflux time was registered andconverted into a value of intrinsic viscosity through Huggins' equation(Huggins, M. L., J. Am. Chem. Soc., 1942, 64, 2716), using the flow timeof the pure solvent at the same experimental conditions (same viscometerand same temperature). A single polymer solution was used to determine[η].

Comonomer (C₂ and C₄) Content

The content of comonomers was determined by infrared (IR) spectroscopyby collecting the IR spectrum of the sample vs. an air background with aFourier transform infrared spectrometer (FTIR). The instrument dataacquisition parameters were:

purge time: 30 seconds minimum

collect time: 3 minutes minimum

apodization: Happ-Genzel

resolution: 2 cm−1.

Sample Preparation—Using a hydraulic press, a thick sheet was obtainedby compression molding about 1 g of sample between two aluminum foilsheets. A small portion was cut from the resulting sheet to mold a film.The film thickness was set to have a maximum absorbance of the CH2absorption band at ˜720 cm−1 of 1.3 a.u. (% Transmittance>5%). Themolding conditions were carried out at a temperature of about 180±10° C.(356° F.) and a pressure of about 10 kg/cm2 (142.2 psi) for about oneminute. The pressure was then released. The sample was removed from thepress and cooled to room temperature. The spectrum of the pressed filmsample was recorded as a function of absorbance vs. wavenumbers (cm−1).The following measurements were used to calculate ethylene (C₂) and1-butene (C₄) contents:

Area (At) of the combination absorption bands between 4482 and 3950cm−1, which was used for spectrometric normalization of film thickness.

Area (AC2) of the absorption band due to methylenic sequences (CH2rocking vibration) in a range of 660-790 cm−1 after a proper digitalsubtraction of an isotactic polypropylene (IPP) and a C₂C₄ referencesspectrum.

The factor of subtraction (FCRC4) between the spectrum of the polymersample and the C₂C₄ reference spectrum: The reference spectrum wasobtained by performing a digital subtraction of a linear polyethylenefrom a C₂C₄ copolymer to extract the C₄ band (ethyl group at ˜771 cm−1).

The ratio AC2/At was calibrated by analyzing ethylene-propylene standardcopolymers of reference compositions, as determined by NMR spectroscopy.

The assignments of the spectra, the evaluation of triad distribution andthe composition were made according to Kakugo (“Carbon-13 NMRdetermination of monomer sequence distribution in ethylene-propylenecopolymers prepared with δ-titanium trichloride-diethylaluminumchloride,” M. Kakugo, Y. Naito, K. Mizunuma and T. Miyatake,Macromolecules, 1982, 15, 1150).

To calculate the ethylene (C₂) and 1-butene (C₄) content, calibrationcurves were obtained by using reference samples with ethylene and1-butene that were detectable by 13C NMR.

Calibration for ethylene—A calibration curve was obtained by plottingAC2/At versus ethylene molar percent (% 2m), and the coefficients aC2,bC2 and cC2 were then calculated via linear regression.

Calibration for 1-butene—A calibration curve was obtained by plottingFCRC4/At versus butane molar percent (% C4m), and the coefficients aC4,bC4 and CC4 were then calculated via linear regression.

The spectra of the evaluated samples were recorded and then (At), (AC2)and (FCRC4) were calculated.

The ethylene content (% molar fraction C2m) of the sample was calculatedas follows:

${\% C2m} = {{- b_{C2}} + \frac{\sqrt{b_{C2}^{2} - {4 \cdot a_{C2} \cdot \left( {c_{C2} - \frac{A_{C2}}{A_{t}}} \right)}}}{2 \cdot a_{C2}}}$

The 1-butene content (% molar fraction C4m) of the sample was calculatedas follows:

${\% C4m} = {{- b_{C4}} + \frac{\sqrt{b_{C4}^{2} - {4 \cdot a_{C4} \cdot \left( {c_{C4} - \frac{{FCR}_{C4}}{A_{t}}} \right)}}}{2 \cdot a_{C4}}}$

where aC4, bC4, cC4 aC2, bC2, cC2 were the coefficients of the twocalibrations.

Changes from mol % to wt % were calculated by using molecular weights ofthe compounds.

Amount (wt %) of comonomer of components B-C were calculated by usingthe following relationship:

Com _(tot) =WaCom _(A) +WbCom _(B) +WcCom _(C)

wherein Wa, Wb and We were the relative amount of components A, B and C,respectively, and (A+B+C=1).

Com_(tot), COM_(A), COM_(B) and ComC were the amounts of comonomer inthe total composition (tot) and in components A-C.

Example 1—Preparation of the Polyolefin Composition Component T2

Catalyst Precursor:

The solid catalyst component used in the polymerization was aZiegler-Natta catalyst component supported on magnesium chloride (MgCl₂)containing titanium and diisobutylphthalate as an internal donor. Aninitial amount of microspheroidal MgCl₂·2.8C₂H₅OH was prepared accordingto Example 2 of U.S. Pat. No. 4,399,054, but operating at 3,000 rpminstead of 10,000 rpm. The resulting adduct was subjected to thermaldealcoholation at increasing temperatures from 30-130° C. in a nitrogencurrent until the molar alcohol content per mol of Mg was about 1.16.Into a 1000 mL four-necked round flask, purged with nitrogen, 500 mL ofTiCl₄ were introduced at 0° C. While stirring, 30 grams of themicrospheroidal MgCl₂·1.16C₂H₅OH adduct were added. The temperature wasraised to 120° C. and maintained for 60 minutes. During the temperatureincrease, an amount of diisobutylphthalate was added to produce aMg/diisobutylphthalate molar ratio of about 18. After 60 minutes,stirring was stopped, the liquid was siphoned off, and the treatmentwith TiCl4 was repeated at 100° C. for 1 hour in the presence of anamount of diisobutylphthalate to produce a Mg/diisobutylphthalate molarratio of about 27. The stirring was then stopped. The liquid wassiphoned off, and the treatment with TiCl₄ was repeated at 100° C. for30 min. After sedimentation and siphoning at 85° C., the solid waswashed six times with anhydrous hexane (6×100 ml) at 60° C.

Catalyst System and Prepolymerization:

Before introducing the solid catalyst component into the polymerizationreactors, the solid catalyst component was contacted at 30° C. for 9minutes with aluminum triethyl (TEAL) and dicyclopentyldimethoxysilane(DCPMS) at a TEAL/DCPMS weight ratio of about 15 and in such a quantitythat the TEAL/solid catalyst component weight ratio was about 4.

The catalyst system was then subjected to prepolymerization bymaintaining the catalyst system in a liquid propylene suspension at 50°C. for about 75 minutes before introducing the catalyst system into thefirst polymerization reactor.

Polymerization

The polymerization was carried out in continuous mode in a series ofthree gas-phase reactors equipped with devices to transfer the productfrom the first reactor to the second reactor. A propylene-based polymer(A) was produced in the first gas phase polymerization reactor byfeeding the prepolymerized catalyst system, hydrogen (the molecularweight regulator) and propylene, with the components in the gas state,in a continuous and constant flow. The propylene-based polymer (A)coming from the first reactor was discharged in a continuous flow and,after having been purged of unreacted monomers, was introduced, in acontinuous flow, into the second gas phase reactor, together withquantitatively constant flows of hydrogen and ethylene, with thecomponents in a gas state. In the second reactor, a copolymer ofethylene (B) was produced. The product coming from the second reactorwas discharged in a continuous flow and, after having been purged ofunreacted monomers, introduced, in a continuous flow, into the third gasphase reactor, together with quantitatively constant flows of hydrogen,ethylene and propylene, with the components in a gas state. In the thirdreactor, an ethylene-propylene polymer (C) was produced. Polymerizationconditions, molar ratio of the reactants and compositions of theresulting copolymers are shown in Table 1. The polymer particles exitingthe third reactor were subjected to a steam treatment to remove thereactive monomers and volatile substances and then dried. Thereafter,the polymer particles were mixed with a stabilizing additive compositionin a twin screw extruder Berstorff ZE 25 (length/diameter ratio ofscrews: 34) and extruded under a nitrogen atmosphere in the followingconditions:

Rotation speed: 250 rpm;

Extruder output: 15 kg/hour;

Melt temperature: 245° C.

The stabilizing additive composition was made from or containing thefollowing components:

-   -   0.1% by weight of Irganox® 1010;    -   0.1% by weight of Irgafos® 168; and    -   0.04% by weight of DHT-4A (hydrotalcite);        where the percentage amounts refer to the total weight of the        polymer and stabilizing additive composition.

Irganox® 1010 was2,2-bis[3-[,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl)-1-oxopropoxy]methyl]-1,3-propanediyl-3,5-bis(1,1-dimethylethyl)-4-hydroxybenzene-propanoate,and Irgafos® 168 was tris(2,4-di-tert.-butylphenyl)phosphite. Thecharacteristics of the polymer composition, reported in Table 2, wereobtained from measurements carried out on the extruded polymer, whichconstituted the stabilized ethylene polymer composition.

TABLE 1 Polymerization conditions Example Ex 1 1^(st) Reactor -component (A) Temperature ° C. 60 Pressure barg 16 H₂/C³⁻ mol. 0.27Split wt % 22 C²⁻/(C²⁻ + C³⁻) mol 0.94 Xylene soluble of (A) (XS_(A)) wt% 9.3 2^(nd) Reactor - component (B) Temperature ° C. 80 Pressure barg18 H₂/C²⁻ mol. 0.69 C²⁻/(C²⁻ + C³⁻) mol. 0.96 Split wt % 30 3^(rd)Reactor - component (C) Temperature ° C. 60 Pressure barg 14 H₂/C²⁻ mol.0.11 C³⁻/(C²⁻ + C³⁻) mol. 0.44 C⁴⁻/(C²⁻ + C⁴⁻) 0.37 Split wt % 48 Notes:C²⁻ = ethylene (IR); C³⁻ = propylene (IR); C⁴⁻ = 1-butene (IR); split =amount of polymer produced in the concerned reactor. * Calculatedvalues.

The features of the polymer of Example 1 are reported in Table 2.

TABLE 2 Example Ex 1 component A C₂ content wt % 3.0 XSA wt % 9.3 MFRg/10 min 110 split wt % 22 component B XSB* wt % 1.7 C₂ content* wt %100 split wt % 30 MFR g/10 min 35 Component C XSC* wt % 42.0 C₂ content*wt % 54.8 C₄ content* wt % 24.0 split wt % 48 total composition MFR g/10min 2.0 IV on soluble in Xylene at 25° C. dl/g 2.79 C₂ = ethylene; C₄ =1-butene; *calculated

Bitumen from the Polymer of Example 1 and Comparative Example 2

The polymer of example 1 and comparative example 2 were blended withbitumen. The blends contained 4% of the polymers of example 1 (T2) andcomparative example 2 (T2) and 95% of bitumen (T1). The two compositionsmarked as B1 and B2. Comparative example 2 was a commercial polymer SBSsold by Kraton for bitumen mixtures.

Asphalt

Samples of different amount of B1 and B2 were mixed with sand, stone,and gravel to obtain asphalt. The feature of the asphalt obtained wasmeasured. The results are reported in Table 3.

TABLE 3 Amount* Marshall Density ρ_sea Voids Vv wt % Flow mm Kg/dm³ %voids B1-1 5.23 4.00 2.38 2.92 B1-2 4.79 3.06 2.39 3.92 B1-3 4.20 2.252.39 4.01 B1-4 3.87 2.33 2.38 5.05 B2-1 5.15 8.35 2.39 2.63 B2-2 4.675.9 2.41 3.00 B2-3 4.43 4.6 2.42 3.52 B2-4 4.01 4.0 2.39 4.92 *Theamounts of B1 and B2 were measured by ligand extraction according to UNIEN 12697 - 1 - 2012 (Bituminous mixtures - Test methods for hot mixasphalt - Part 1: Soluble binder content). Density was measuredaccording to EN 12697-5 - 2018. Voids were measured according to EN12687-8. Stability and Flow were measured according to EN 12697-34 -2012.

What is claimed is:
 1. Asphalt product comprising: Z1) from 90 wt % to98 wt % of mineral aggregate; and Z2) from 2 wt % to 10 wt % of abitumen composition comprising T1) from 99 wt % to 75 wt % of -bitumen-,and T2) from 1 wt % to 25 wt % of a polymer composition comprising A)5-35% by weight of a propylene ethylene copolymer containing 15% byweight or less of a fraction soluble in xylene at 25° C. (XS_(A)), theamount of the fraction XS_(A) being referred to the weight of A); andfrom 0.5 wt % to 7.0 wt % of ethylene derived units; B) -20-50% byweight of an ethylene homopolymer having 5% by weight or less of afraction soluble in xylene at 25° C. (XS_(B)) referred to the weight of(B); and C) -30-30-60% by weight of a terpolymer of ethylene, propyleneand 1-butene derived units and containing from 45% to 65% by weight ofethylene units; and from 15% to 38% by weight of 1-butene units; andcontaining from 30% to 85% by weight of a fraction soluble in xylene at25° C. (XS_(C)), the amount of ethylene units, 1-butene units, and thefraction XS_(C) being referred to the weight of (C); the amounts of (A),(B) and (C) being referred to the total weight of (A)+(B)+(C), the sumof the amount of (A)+(B)+(C) being 100 wt %; the amounts, wt %, of T1+T2being 100 wt %.
 2. Asphalt product according to claim wherein incomponent T2), Component A ranges from 10% by weight to 30% by weight;Component B ranges from 25% by weight -to 45% by weight; and Component Cranges from 35% by weight -to 55% by weight,
 3. Asphalt productaccording to claim 1, -wherein, in component T2, Component A ranges from15% by weight to 23% by weight; Component B ranges from 30% by weight-to 40% by weight; and Component C ranges from 40% by weight -to 50% byweight.
 4. Asphalt product according to claim 1, wherein, in componentT2), component A) has the -fraction soluble in xylene at 25° C. (XS_(A))of 13 wt % or less.
 5. Asphalt product according to claim 1, wherein, incomponent T2), component B) is an ethylene homopolymer having 4 wt % orless of a fraction soluble in xylene at 25° C. (XS_(B)).
 6. Asphaltproduct according to claim 1, wherein, in component T2), component C) isterpolymer of ethylene, propylene and 1-butene containing from 48% to62% by weight of ethylene units; and from 18% to 33% by weight of1-butene units.
 7. Asphalt product according to claim 1, wherein, incomponent T2), component (A) -has a melt flow rate (230° C./2.16 kg)between 50 and 200 g/10 min.
 8. Asphalt product according to claim 1,wherein, in component T2), -component (B) -has a melt flow rate (230°C./2.16 kg) ranging between 0.1 and 50 g/10 min.
 9. Asphalt productaccording to claim 1, wherein, in component T2), component (A) -has amelt flow rate (230° C./2.16 kg) between 80 and 170 g/10 min. 10.Asphalt product according to claim 1, wherein, in component T2),-component (B) -has a melt flow rate (230° C./2.16 kg) between 0.1 and30 g/10 min.
 11. Asphalt product according to claim 1, wherein, in-component T2) the ethylene homopolymer component -(B) has a density(determined according to ISO 1183 at 23° C.) of from 0.940 to 0.965g/cm³.
 12. Asphalt product according to claim 1, wherein component T2)has -a melt flow rate (230° C./2.16 kg) between from 0.8 to 20.0g/10min.
 13. Asphalt product according to claim 1, wherein -T1 ranges from98 wt % to 80 wt % and T2 ranges from 2 wt % to 20 wt %.
 14. Asphaltproduct according to claim 1, wherein -T1 ranges from 97 wt % to 90 wt %and T2 ranges from 3 wt % to 10 wt %.
 15. Asphalt product according toanyone of claims 1 12c1aim 1 wherein -T1 ranges from 97 wt % to 92 wt %and T2 ranges from 3 wt % to 8 wt %.